Reenforced block structure for electric fixtures



March 14, 1933.

J. G. JACKSON REENFORCED BLOCK STRUCTURE FOR ELECTRIC FIXTURES FiledSept. 21. 1931 2 Sheets-Sheet l ws w ram/W 1 March 14, 1933. J. G.JAcKsoN REENFORCED BLOGK STRUCTURE FOR ELECTRIC FIXTURES Filed Sept. 21,1931 2 Sheets-Sheet 2 INVENTOR d'dl?? 63. rfac/safl 4% W ATTORNEY'S'Patented Mar; 14, 1933 UNITED sTATEs JOHN G. JACKSON, OF DETBOIT,MICHIGAN, ASSIGNOR T0 SQUARE D COMPANY, OFv

lPATENT OFFICE DETROIT, MICI-IIGAN, A CORPORATION OF MICHIGAN BEENFORCEDBLOCK STBUCTURE FOR ELECTRIC FIXTURES Application led September 21,1931. Serial No. 564,243.

This invention relates generally to porcelain bases and refers moreparticularly to those designed for supporting electric parts such asfuse clips and the like.

In the accompanying drawings:

Figure 1 is a perspective view of a fuse box containing a base embodyingmy invention;

Figure 2 is a detail perspective view of the base with electrical partsmounted thereon;

Figure 3 is an edge elevation of the base;

Figure 4 is a cross sectional view taken on the line 4-4 of Figure 3;

Fi re 5 is a detail perspective view of the reen orcement.

Few electrical base materials except porcelain are non-carbonizable butporcelain alone is subject to breakage and initial fracture thereof maycause displacement of live electrical parts mounted thereon,consequently such bases are unsatisfactory.

My invention includes means for increasing the strength of the porcelainby the introduction into slots or recesses therein of steel and cement,the construction and arrangement being such that the cement at arelatively low temperature may be placed into the recesses and embodiesin its composition quulities which permit it to bond steel to porcelainwithout entailing fracture of the porcelain due to any difference inexpansion or contraction of steel and of porcelain over normal ranges oftemperatures of use or of handling. Such reenforcement of porcelain bymeans of steel rods or bars has not been possible by direct introductionof steel into porcelain `vhen molded therein, as subsequent firingOperations at high temperatures cause 'expansion and contraction ofsteel and porcelain as Well as adverse chemical actions between the twomaterials.

Referring now to the drawings, 1 is a base embodying my inventionmounted within a suitable box or container 2 andpsupporting suitablefuse clips 3 and their electrical conluctors 4 and terminals 5. Asshown, this base is provided in the top and bottom thereof With suitablerecesses 6 and 7 respectively for receiving the electric parts justmentioned and is provided in opposite longitudinal edges 8 and 9 withlongitudinally extending channels or recesses 10 and 11 respectivelyhaving keying grooves or slots 12 and 13 in certain walls thereof.Suitably deformed or twisted steel bars 16 are placed as far aspractical in the recesses 10 and 11 upon opposite sides of the neutralaxis of the base and are held in place by cement 17. Preferably thiscement comprises a mixture of sulphur and finely ground fiint and isplaced in the recesses while in a molten condition. Such a cement bondsto steel and to porcelain and at the temperature of application does notcause objectionable strains to be set up in the structure. In fact, thebond between the steel and porcelain is such that the parts are heldfirmly together without subsequent tendency to fract-ure under variousnormal conditions of change in temperature whether Sudden or slow, andaffords a greater resistance to fracture than when porcelain alone isemployed as a base material. However, should the base 1 be fractured asa resultof undue pressure or mechanical shock, the electrical parts 3, 4and 5 respectively thereon will not be appreciably displaced. Thus asafer and more durable structure is provided.

While it is believed that from the foregoing description the nature andadvantages of the invention will be' readily apparent, I desire to haveit understood that I do not limit myself to What is herein shown anddescribed and 'that such changes may be resorted to when desired as fallwithin the scope of What is claimed.

What I claim as my invention is:

1. In combination, a porcelain base havlng a recess in an edge thereof,cement in the recess, and a steel reenforcement in the cement.

2. In combination, a porcelain base provided in one longitudinal edgethereof with a longitudinally extending recess, cement in the recess,and strips of steel embedded in the cement and extending longitudinallyof the recess.

3. In combination, a porcelain base having a recess, a steelreenforcement in the recess, and a connection between the steel andporcelain including cement in the recess.

1'In combination, a. substantially flat porcelain base provided in oneedgeA witlr a longitudinally extending channel having an anchoragegroove in a wall thereof, steel members Within and extendinglongitudinally of the channel, and a connection between said members andporcelain including cement anchored Within the channel and en- Velopingsaid steel members.

5. In combination, a substantially flat elongated porcelain baseprovided in opposite longitudinal edges thereof throughout substantiallythe length of the base with longitudinally extending laterally openingChannels, cement within said channels, and steel reenforcing membersembedded within the cement and extending throughout substantially theentire length of the Channels, said channels and steel reenforcementshaving p'ortionsupon opposite sides of the neutral axis of the base.

6. In combination, a base of vitreous material provided in one edge witha long'itudinally extending recess, portions of the ress 25.;ben`g uponopposite sides of the neutral axis of the base, reenforcing means forthe base including steel members in the recess upon n oppo'site sides ofthe neutral axis of the base,

and means in the recess bonding the steel members to the base ofvitreous material.

7. Inhcombination, a porcelain base provided in one edgewith alongitudinally extending recess, a steel reenforcement in the recess,and cement within the recess bonding 'the steel reenforcement to theporcelain base.

8. In combination, a porcelain base having a recess therein, a steelreenforcement for the base located within said recess, and means withinthe recess bonding the steel reenforce- 40.nent to the porcelain base.

9. In combination, a porcelain base having a recess therein, a steelreenforcement for the base located Within said recess, and means forbonding the steel reenforcement to the base including a cementcomprising a mixture 'of sulphur and finely ground fiint within therecess and enveloping the steel reenforcement.

10. In combination, a porcelain base pro- -vided With a longitudinallyextending channel having an anchorage groove in a wall thereof, a steelmember within and extending longitudinally of the channel, and aconnection between said member and porcelain including cement envelopingsaid member Within said channel and engaging said anchorage groove. I

11. In combination, a porcelain base having an elongated recess therein,one Wall of said recess having a longitudinally extending ature. SON.

anchorage groove, a steel member within and 4 extending longitudinallyof the recess, and a connection between said member and porcelainincluding cement within said recess and engaging said anchorage groove.

